CVE-2026-4963: huggingface smolagents Incomplete Fix CVE-2025-9959 local_python_executor.py evaluate_with code injection
Vulnerability summary
CVE-2026-4963 is a critical (CVSS 10.0) vulnerability in huggingface smolagents. EPSS estimates a 0.59% chance of exploitation in the next 30 days, higher than 48% of scored vulnerabilities. 5 public exploits are recorded.
Not severe (CVSS 5.3, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Timeline
- 27-03-2026PublishedVulnerability first disclosed.
- 31-03-2026Last modifiedVulnerability information updated.
Description
A weakness has been identified in huggingface smolagents 1.25.0.dev0. This affects the function evaluate_augassign/evaluate_call/evaluate_with of the file src/smolagents/local_python_executor.py of the component Incomplete Fix CVE-2025-9959. This manipulation causes code injection. It is possible to initiate the attack remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.
CVSS metrics
9 scores · 3 sources · 4 versions- OSV · PypiEcosystem advisory · calculated5.3MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
- NVDNIST2.1LowCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XDiffers
- CVE.orgCNA6.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L/E:P/RL:X/RC:RDiffers
- OSV · PypiEcosystem advisory · calculated6.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:LDiffers
- NVDNIST7.5HighAV:N/AC:L/Au:N/C:P/I:P/A:P
EPSS trend
Probability
0.59%
Chance of exploitation in the next 30 days
Percentile
48%
Versus all other CVEs
30-day change
Decrease -0.15 pp
From 0.73% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
5 found35B7D46E892266A0Ed6Dbe57802858Be
Maturity: poc
7146F45960F79Bc1E2976Fed526E0A9B
Maturity: poc
Exploit Reference (vuldb.com)
Maturity: unknown
Weaknesses
CWE · root cause- CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream ComponentThe product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
- CWE-94Improper Control of Generation of CodeThe product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
Affected systems
Known conditions: network-reachable, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.
Huggingface1 product
- smolagents1.25.0.dev0 | 1.25.0:dev0
PyPI1 product
- smolagents≤ 1.25.0.dev0
2 vendors · 2 products
References
11 links
- pypi.org/project/smolagentsPACKAGE